NAME

endutxent, getutxent, getutxid, getutxline, pututxline, setutxent - user accounting database functions

 SYNOPSIS

#include <utmpx.h>

void endutxent(void);
struct utmpx *getutxent(void);
struct utmpx *getutxid(const struct utmpx *id);
struct utmpx *getutxline(const struct utmpx *line);
struct utmpx *pututxline(const struct utmpx *utmpx);
void setutxent(void);

 DESCRIPTION

These functions provide access to the user accounting database.

The getutxent() function reads in the next entry from the user accounting database. If the database is not already open, it opens it. If it reaches the end of the database, it fails.

The getutxid() function searches forward from the current point in the database. If the ut_type value of the utmpx structure pointed to by id is BOOT_TIME, OLD_TIME or NEW_TIME, then it stops when it finds an entry with a matching ut_type value. If the ut_type value is INIT_PROCESS, LOGIN_PROCESS, USER_PROCESS, or DEAD_PROCESS, then it stops when it finds an entry whose type is one of these four and whose ut_id member matches the ut_id member of the utmpx structure pointed to by id. If the end of the database is reached without a match, getutxid() fails.

The getutxid() or getutxline() may cache data. For this reason, to use getutxline() to search for multiple occurrences, it is necessary to zero out the static data after each success, or getutxline() could just return a pointer to the same utmpx structure over and over again.

There is one exception to the rule about removing the structure before further reads are done. The implicit read done by pututxline() (if it finds that it is not already at the correct place in the user accounting database) will not modify the static structure returned by getutxent(), getutxid() or getutxline(), if the application has just modified this structure and passed the pointer back to pututxline().

For all entries that match a request, the ut_type member indicates the type of the entry. Other members of the entry will contain meaningful data based on the value of the ut_type member as follows:

ut_type Member
Other Members with Meaningful Data
EMPTY
No others
BOOT_TIME
ut_tv
OLD_TIME
ut_tv
NEW_TIME
ut_tv
USER_PROCESS
ut_id, ut_user (login name of the user), ut_line, ut_pid, ut_tv
INIT_PROCESS
ut_id, ut_pid, ut_tv
LOGIN_PROCESS
ut_id, ut_user (implementation-dependent name of the login process), ut_pid, ut_tv
DEAD_PROCESS
ut_id, ut_pid, ut_tv

The getutxline() function searches forward from the current point in the database until it finds an entry of the type LOGIN_PROCESS or USER_PROCESS which also has a ut_line value matching that in the utmpx structure pointed to by line. If the end of the database is reached without a match, getutxline() fails.

If the process has appropriate privileges, the pututxline() function writes out the structure into the user accounting database. It uses getutxid() to search for a record that satisfies the request. If this search succeeds, then the entry is replaced. Otherwise, a new entry is made at the end of the user accounting database.

The setutxent() function resets the input to the beginning of the database. This should be done before each search for a new entry if it is desired that the entire database be examined.

The endutxent() function closes the user accounting database.

These interfaces need not be reentrant.

 RETURN VALUE

Upon successful completion, getutxent(), getutxid() and getutxline() return a pointer to a utmpx structure containing a copy of the requested entry in the user accounting database. Otherwise a null pointer is returned.

The return value may point to a static area which is overwritten by a subsequent call to getutxid() or getutxline().

Upon successful completion, pututxline() returns a pointer to a utmpx structure containing a copy of the entry added to the user accounting database. Otherwise a null pointer is returned.

The endutxent() and setutxent() functions return no value.

 ERRORS

No errors are defined for the endutxent(), getutxent(), getutxid(), getutxline() and setutxent() functions.

The pututxline() function may fail if:

[EPERM]

The process does not have appropriate privileges.

 EXAMPLES

None.

 APPLICATION USAGE

The sizes of the arrays in the structure can be found using the sizeof operator.

 FUTURE DIRECTIONS

None.

 SEE ALSO

<utmpx.h>.